Patterns of change in the population and spatial distribution of oriental white storks (Ciconia boyciana) wintering in Poyang Lake

Using total counts in simultaneous annual surveys, we monitored the population size and spatial distribution of oriental white storks （Ciconia boyciana） wintering in Poyang Lake between 1998 and 2011. Results showed that Poyang Lake wetland is an important wintering ground for oriental white storks, with an annual average population number of 2 305＋326. The population sizes in 2004, 2005, 2010, and 2011 were higher than the highest-ever estimate of its global population. In 2005, we recorded 3 789 individuals, which was the maximum population number within the period of 1998-2011. The storks inhabited 52 lakes, with the greatest distance between these lakes being 180.3 km. The storks presented a clustered distribution pattern in the Poyang Lake wetland, irrespective of the number of individuals or occurrence frequencies. Shahu, Dahuchi, Banghu, and Hanchihu were most frequently used lakes and had the largest annual average numbers of storks. There was a significant positive correlation between occurrence frequency and annual average number of storks in the lakes. Most of the lakes important for storks were covered by existing nature reserves, though some lakes outside the reserves were also frequently used. About 64.9%＋ 5.5% of the storks were found in nature reserves. In addition, the storks more frequently used and clumped in significantly larger flocks in lakes within nature reserves than lakes outside.

Observation on behavior of adult oriental white stork in nesting period

Based on the field observation on the parental behavior of Oriental White Stork (Ciconia boyciana) during their brooding period, this paper describes the breeding style, feeding behavior, water chicks, protect chicks, etc. A Ritual “behavior—Culmen Knocking/bill clattering” was observed and which is divided into three styles with deferent meanings. This behavior plays an important role during this season.

Genetic structure of the oriental white stork (Ciconia boyciana): implications for a breeding colony in a non-breeding area

The oriental white stork (Ciconia boyciana) is a threatened species, and their numbers are still in decline due tohabitat loss and poaching. China is a breeding and main wintering area for this animal and in recent years someindividuals have been found breeding in wintering areas and at some stopover sites. These new breeding coloniesare an exciting sign, however, little is understood of the genetic structure of this species. Based on the analysis ofa 463-bp mitochondrial DNA (mtDNA) control region, we investigated the genetic structure and genetic diversity of66 wild oriental white storks from a Chinese population. We analyzed the sequences of 66 storks obtained in thisstudy and the data of 17 storks from a Japanese population. Thirty-seven different haplotypes were detected amongthe 83 samples. An analysis of molecular variance showed a significant population subdivision between the twopopulations (FST = 0.316, P < 0.05). However, the phylogenetic analysis revealed that the samples from the differentpopulations did not form separate clusters and that there were genetic exchanges between the two populations.Compared with the Japanese population, the Chinese population had a relatively higher genetic diversity with ahaplotype diversity (h ± SD) of 0.953 ± 0.013 and a nucleotide diversity (π ± SD) of 0.013 ± 0.007. The high haplotypediversity and low nucleotide diversity indicate that this population might be in a rapidly increasing period from asmall effective population. A neighbor-joining tree analysis indicated that genetic exchange had occurred betweenthe newly arisen southern breeding colony and the northern breeding colony wintering in the middle and lowerYangtze River floodplain. These results have important implications for the conservation of the oriental white storkpopulation in China.